Professor Noni Franklin-Tong

Emeritus Professor of Plant Cell BiologyResearch Fellow

Contact details

School of BiosciencesUniversity of Birmingham
Edgbaston
Birmingham
B15 2TT
UK

About

Noni Franklin-Tong’s research focuses on the cellular mechanisms involved in the model cell-cell recognition system of self-incompatibility (SI) in Papaver rhoeas (the Field Poppy). She is recognized at an international level for her work in the field of plant cell biology. Specifically she has made major contributions to the field of self-incompatibility, a field that has high importance in relation to the future focus on food security. Her research has had a world-wide impact in the broader fields of plant cell signalling, the plant cytoskeleton and programmed cell death in plants.

Her work includes several publications in Nature, has been highlighted in News & Views and “Editor’s Choice” in Nature and in “Leading Edge” in Cell. Noni is currently Secretary General for the International Association of Sexual Plant Reproduction Research (IASPRR) and has served on the Society for Experimental Biology (SEB) Plant Biology Committee for more than 10 years and has also served on Council. She is currently on the Editorial Board of Journal of Experimental Botany, and Sexual Plant Reproduction, and is a Review Editor for Frontiers in Plant Physiology.

Noni has a long-term commitment to enthusing children about science education and has been involved in providing the general public with a broader understanding of science through a number of activities. She was one of the original BBSRC Regional Coordinators of the Schools Liaison Scheme.

Qualifications

BSc (Hons) Biological Sciences (University of Birmingham) 1982

PhD Department of Genetics (University of Birmingham) 1986

Biography

Noni Franklin-Tong was born in London, U.K. She received her BSc in Biological Sciences and PhD in Genetics from the University of Birmingham.Most of her career has been based at Birmingham, though she has worked for brief periods of time inUmeå, Sweden, ICMB, University of Edinburgh and UMass, Amherst, USA. She obtained a BBSRC Advanced Research Fellowship in 1992, was appointed to a lectureship in 1997, and a Chair in Plant Cell Biology (2004-2014). Following breast cancer she is partially retired, working part-time research-only (2014-).

Research

Targets and mechanisms involved in the self-incompatibility response in Papaver rhoeas pollen

Sexual reproduction in higher plants involves pollination, involving specific interactions between pollen and pistil. A key mechanism to prevent inbreeding is self-incompatibility (SI), which is a controlled by a single, multi-allelic S-locus. Incompatible ("self") pollen is rejected and compatible ("non-self") pollen is allowed to fertilize the plant.

My lab is investigating the signalling cascades, targets and mechanisms regulating pollen tube tip growth inhibition induced by SI in Papaver. The "self" interaction triggers a Ca2+-dependent signalling network, resulting in incompatible pollen tube tip growth being inhibited and programmed cell death being induced. Our long-term goal is to establish how the different components integrate and interact in what has turned out to be a complex signalling network. Currently research falls into several areas:

1. Investigations into programmed cell death in the SI response.

Programmed cell death (PCD) is an important mechanism responsible for the controlled death of targeted cells in animal and plant cells. We demonstrated that PCD is triggered in incompatible pollen and identified several caspase-like activities (a VEIDase and a LEVDase) that are activated by an incompatible SI response. We identified increases in reactive oxygen species (ROS) and nitric oxide (NO) during SI-PCD and are currently investigating their role in incompatible pollen using a mass spectrometry approach. We are exploring further mechanisms involved in PCD with Dr Maurice Bosch (IBERS).

2. Alterations in the actin cytoskeleton

In many cells alterations to the cytoskeleton are the first visible response to extracellular stimuli. We have shown that both the actin and microtubule cytoskeleton are important target for SI signals, and recently obtained evidence for crosstalk between actin and microtubules. In animal cells sustained actin depolymerization can stimulate apoptosis via caspases. We have shown that actin depolymerization can trigger PCD in pollen and propose that the formation of highly stable punctate actin foci is integral to SI-PCD. The actin-binding proteins cyclase-associated protein (CAP) and actin depolymerizing factor (ADF) key downstream targets of SI-PCD and co-localize to the foci.

We previously identified soluble inorganic pyrophosphatases (sPPases) as a novel target for phosphorylation, as Pr-p26.1a/b was phosphorylated after SI.We are analysing the phosphorylation sites on Pr-p26.1a/b using mass spectrometry and using site-directed mutagenesis to attempt to establish those involved in sPPase phospho-regulation. We are also analysing the CDPK(s) involved in SI-induced phosphorylation of Pr-p26.1a/b.

4.Analysis of SI-induced acidification

We previously observed a major acidification of the pollen cytosol during PCD in incompatible pollen. We recently measured temporal alterations in cytosolic pH ([pH]cyt); they were surprisingly rapid, reaching pH 6.4 within 10 min of SI induction, stabilizing by 60 min at pH 5.5. Exploring the role of this, we found that the [pH]cyt acidification is an integral and essential event for SI-induced PCD. We demonstrated that [pH]cyt acidification is necessary and sufficient for triggering several key hallmark features of the SI-PCD signalling pathway, notably the activation of a DEVDase/caspase-3-like activity and formation of SI-induced punctate actin foci.

5. Integrating signals and targets involved in mediating SI-PCD in incompatible pollen It has become evident that many of the PCD events are intertwined. Current focus is on understanding the mechanisms involved. The long-term goal is to establish how the different components integrate and interact in what has turned out to be a complex signalling network.

6. Investigating the functionality of Papaver S-determinants in heterologous systems

We recently showed that the pollen S-determinant, PrpS could be expressed in compatible Arabidopsis thaliana, a self-compatible model plant. Exposing transgenic A. thaliana pollen to recombinant Papaver PrsS protein triggered remarkably similar responses to those observed in incompatible Papaver pollen. This demonstrated that PrpS is functional in a species with no SI system that diverged ~140 million years ago, and suggests that the Papaver SI system uses cellular targets that are, perhaps, common to all eudicots and that endogenous signaling components can be recruited to elicit a response that most likely never operated in this species. We are currently exploring if the Papaver S-determinants are functional in other plant species/genera and also if they work in other cell types.

7. We are pursuing possible commercial aspects of using SI, by investigating whether poppy SI can be transferred to other species in collaboration with Dr Barend de Graaf (Cardiff) and Dr Wendy Harwood (JIC). This follows on from filing a patent in 2008. This is a very exciting opportunity; LES College KT Development funding(£20,000) allowed us to pursue obtaining further data to consolidate the patent. Links have been made with PBL, who are currently marketing this application, which could be of immense value to plant breeders in the production of F1 hybrids.

V.E. Franklin-Tong (ed.) Self-Incompatibility in Flowering Plants – Evolution, Diversity, and Mechanisms. Publ. Springer-Verlag Berlin Heidelberg 2008. This is the first monograph on this topic for 30 years.